@conference {79027,
	title = {Effect of resolving a sub-clinical uterine infection on plasma and follicular fluid steroid concentrations in early lactation dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {72},
	year = {2012},
	month = {Jan},
	pages = {231-235},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Sub-clinical endometritis (scEndo) in early lactation affects ovarian follicle dynamics, delays a return to cyclicity, with changes in plasma and follicular fluid (FF) amino acid concentrations around the time of rebreeding. This study examined the effect of resolving scEndo in early lactation on plasma and FF oestrogen, progestagen, androgen and corticosteroid concentrations at the time of rebreeding in 46 dairy cattle. On D42 postpartum, cows were classified as having scEndo, clean or having resolved scEndo cased on uterine cytology on D21 of > 18\% polymorphonuclear (PMN) cells amongst uterine nucleated cells. On D42 and D63 follicular and plasma samples were collected and steroid concentrations analysed. On D21 and D42, 35\% and 7\% of cows respectively were classified as having scEndo, with 81\% of scEndo cows having self-resolved the infection by D42. In those cows that resolved scEndo, none of the plasma or FF steroid concentrations changed between D42 and D63, except for plasma progesterone (P = 0.08). Using a low (4\%PMN) threshold to classify scEndo did not identify any significant changes in steroid concentrations. In contrast to previously described changes in plasma and FF amino acid concentrations, there were no significant effects on steroid concentrations when cows self-resolved a sub-clinical uterine infection.},
	issn = {1176-5283},
	author = {Lopdell TJ and Berg MC and Green MP and Back PJ}
}
@conference {75925,
	title = {Effect of sub-clinical uterine infection on plasma amino acid concentrations in early lactation dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {291-295},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {This study examined the effect of sub-clinical endometritis (scEndo) in early lactation on plasma amino acid (AA) concentrations of dairy cattle (n = 46). On D21 and D42 postpartum cows were classified as having scEndo or Clean based on uterine cytology; >18\% polymorphonuclear (PMN) cells amongst uterine nucleated cells. On D21 and D42, 35\% and 7\% of cows respectively were classified as having scEndo, with a large proportion of scEndo cows having self-resolved the infection by D42. Plasma serine concentrations were higher (P <0.03) in scEndo compared to Clean cows irrespective of day postpartum. Independent of uterine status, three AA altered (P <0.05) in concentration between D21 and D42. The effect of change in uterine status from D21 to D42 resulted in decreased (P =0.05) concentrations of three AA in cows that resolved infection. The use of a lower cut-off to define scEndo (4\% vs 18\%PMN) identified four AA, instead of three AA at 18\% that differed over time. Thus, during the early postpartum period, the concentrations of a number of AA change (P <0.05) irrespective of uterine health. However, scEndo is associated with an increase in plasma serine and a decrease in the concentration of several AA when a uterine infection is resolved.},
	issn = {1176-5283},
	author = {Lopdell T and Berg MC and Green MP and Back PJ}
}
@conference {75926,
	title = {Sub-clinical uterine infection is associated with altered amino acid concentrations of follicular fluid in early lactation dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {71},
	year = {2011},
	month = {Jan},
	pages = {296-300},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Invercargill},
	abstract = {The effect of sub-clinical endometritis (scEndo) in early lactation on follicular amino acid (AA) concentrations was determined. On D21 and D42 postpartum cows were classified as having scEndo or Clean based on uterine cytology; >18\% polymorphonuclear (PMN) cells amongst uterine nucleated cells. On D21 and D42, 35\% and 7\% of cows respectively were classified as having scEndo, with a large proportion of scEndo cows having self-resolved the infection by D42. Follicular histidine (P = 0.04), as well as alanine, aspartate and serine concentrations (P <0.1) were higher in scEndo compared with Clean cows. The effect of change in uterine status from D21 to D42 resulted in increased (P <0.1) follicular glutamate, ornithine and valine concentrations in cows that resolved infection. Correlation coefficients were determined to test the relationship between plasma and follicular AA concentrations. A greater number of AA in Resolved cows showed no relationship between plasma and follicular concentrations compared to Clean cows. Thus, scEndo is associated with an increase in follicular histidine and an increase in the concentration of several AA when a uterine infection is resolved. This study demonstrates that scEndo may be responsible for long-term alterations in follicular AA concentrations that could potentially result in altered oocyte viability.},
	issn = {1176-5283},
	author = {Back PJ and Lopdell T and Berg MC and Green MP}
}
@conference {69530,
	title = {Differences in follicle dynamics and the importance of luteal support in young and old cohorts of genetically identical dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {70},
	year = {2010},
	month = {Jun},
	pages = {303-305},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {There has been a documented decrease in fertility in the modern dairy cow selected for milk yield (Pryce et al.,2004). This emphasises the need for farmers in a seasonal grass-based system such as that in New Zealand to correctly manage herd genetics in conjunction with nutrition to optimise cow reproductive performance. The question remains however as to the relative influence and interdependence of these two factors in establishing a pregnancy, as an optimal size for the ovulatory follicle is directly related to successful conception and pregnancy (Perry et al., 2005).},
	issn = {1176-5283},
	author = {Green MP and Back PJ and Berg MC}
}
@conference {60936,
	title = {Effects of sub-clinical endometritis on ovarian follicular activity in postpartum dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {32-36},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The effects of sub-clinical endometritis (scEndo) on ovarian follicular activity in pasture-fed dairy cows were determined. The uterine-health status of lactating dairy cows (n = 169) was assessed on day (D) 21 ({\textpm} 3 days) postpartum by Metricheck. In a sub-population (n = 47; 32 clean, 15 scEndo), Metricheck assessment was repeated on D42 and uterine cytology undertaken on D21 and D42 [scEndo = polymorphicnuclear (PMN) cells >18\%]. Follicular activity was assessed by ultrasound on D42 and D63. Metricheck evaluation revealed that the proportion of cows with scEndo was 15/169 (8.9\%) and 4/47 (8.5\%) on D21 and D42 respectively. Irrespective of the method used to determine scEndo, dominant (P <0.001) but not subordinate (P >0.1) follicles were larger and grew faster on D63 than on D42. Based on the D21 Metricheck but not the \%PMN classification, dominant follicles of scEndo cows were larger and grew faster (P = 0.02) than those in clean cows. No overall effect of uterine status was found on the subordinate follicles, although these tended (P = 0.06) to be larger on D63 than on D42 but only in clean cows. Thus early postpartum scEndo appears to modulate the subsequent size of the dominant follicle. However, it remains to be determined whether this affects the subsequent fertility of these cows. },
	issn = {1176-5283},
	author = {Back PJ and Ledgard AM and Beaumont S and Berg MC and Peterson AJ and McNatty KP and Green MP}
}
@conference {60937,
	title = {Prevalence and identification of systemic markers of sub-clinical endometritis in postpartum dairy cows},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {37-42},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The prevalence of sub-clinical endometritis (scEndo) and identification of serum markers of scEndo was investigated in pasture-fed, postpartum dairy cows. Mixed age lactating dairy cows (n = 169) were examined for uterine health status on day (D) 21 postpartum ({\textpm} 3 days) by Metricheck classification. On D42 in a subpopulation (n = 47; 32 clean, 15 scEndo) Metricheck assessment was repeated and uterine cytology undertaken on D21 and D42 [scEndo = polymorphicnuclear (PMN) cells >18\%]. Uterine bacteriology, as well as haematological, biochemical and milk parameters were also measured. The prevalence of scEndo was 15/169 (8.9\%) and 4/47 (8.5\%) cows on D21 and D42 respectively. A high incidence of self-resolving scEndo (11/15, 73\%) was revealed. Numerous species of pathogenic bacteria were isolated from both scEndo and clean cows. Despite the uterine infection being sub-clinical, systemic markers were detectable as on D21 and D42 haematological and biochemical parameters differed. Irrespective of the scEndo classification method used, the mean blood neutrophil concentration was higher (P <0.05) and plasma albumin lower (<0.05) in scEndo cows compared to clean cows. Milk fat and protein \% also differed (P <0.05) between scEndo and clean cows. The monitoring in early lactation of these markers could aid identification of scEndo, thereby preventing potentially detrimental effects on subsequent fertility. },
	issn = {1176-5283},
	author = {Green MP and Ledgard AM and Berg MC and Peterson AJ and Back PJ}
}
